Not the dialogue itself, but the pressure that dialogue creates between two characters who can’t get what they need from each other.
This allows the audience to connect to the storyof the scene, and while we may lose some of the specific words within Sorkin’s complex verbal gymnastics, no one can escape the power of the scene, or the meaning that those words contain.
We learn that meaning not through the words themselves. But through thewaythose words are spoken, and the powerful needs that drive the characters to say them.
via THE SOCIAL NETWORK: Is The Audience Listening To Your Dialogue? | Write Your Screenplay.
Pretty quick article on screenwriting dialogue. Useful thoughts.